Use of AccuVein AV500 in differentiating veins from arteries during microsurgical varicocelectomy

Abstract

A varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. This physical condition is present in 11.7% of men, 25.4% of men with abnormal semen analysis and 40% of men presenting with infertility.1 Surgical treatment by ligation of the venous plexus is performed to improve semen analysis parameters and decrease sperm DNA damage.2, 3 Although there are no recent data, a previous meta-analysis showed that varicocelectomy might improve outcomes following assisted reproductive techniques in oligozoospermic men.4 The following surgical approaches may be used: scrotal operation, inguinal approach, high ligation, microsurgical inguinal or subinguinal approach, and laparoscopy. Microsurgical varicocelectomy is considered the most effective approach due to the fewer complications and lower recurrence rates associated with it, when compared with the other techniques.5 However, even if the microsurgical approach was chosen, severe complications remained, including iatrogenic testicular artery ligation (1%) and secondary testicular atrophy (5% in iatrogenic artery ligation).6 In a randomised controlled trial, the use of Doppler ultrasonography during microsurgical varicocelectomy shortened operative time and increased the number of protected arteries and ligated spermatic veins.7 Therefore, we adapted subinguinal microsurgical varicocelectomy using Doppler ultrasonography. However, this procedure requires microsurgical training and the use of Doppler ultrasonography to identify each blood vessel. These factors make the procedure complex and extend the operative time. In rare cases, it may also be difficult to differentiate the arteries and veins. In this study, we aimed to evaluate the ability of AccuVein® (AV500, AccuVein Inc., Medford, New York, USA) to identify internal spermatic veins in real time during microsurgical varicocelectomy. AccuVein® is a highly portable vascular access imaging device that can support the decision of the optimal venipuncture site and avoid potential complications. Projected near-infrared light through the skin is absorbed by reduced haemoglobin in the vein and is reflected by the surrounding tissue. Arteries with oxidised haemoglobin and lymphatic vessels without haemoglobin reflect near-infrared light like the surrounding tissue. After the reflected light is captured and processed, the information is digitally projected onto the surface of the skin. The veins are illuminated with green lines, and other tissues including arteries and lymphatic vessels are depicted as black on the skin surface. Therefore, it provides a real time, accurate image of the patient's venous pattern. The device is also widely applied for various surgical procedures, including lymphatic venous anastomosis and trocar insertion during robot-assisted radical prostatectomy.8-10 In this pilot study, 10 male infertile patients who underwent microsurgical varicocelectomy with subinguinal approach under AccuVein® visualisation between July 2020 and December 2020 in the Yokohama City University Medical Center were enrolled. Briefly, after making an incision in the skin, the spermatic cord was detected outside the external inguinal ring and pulled out of the wound. The ligation of the external spermatic veins and the incision of the external, cremasteric and internal spermatic fascia were performed. The remaining internal spermatic cord was observed to identify spermatic veins from arteries using the surgical microscope. In this microscopic procedure, near-infrared light from AccuVein® was continuously projected on the spermatic cord. Once the blood vessels have been identified by normal visible light observation, the visible light is switched off and the blood vessels shown as green lines by AccuVein® are recorded as internal spermatic veins. Subsequently, using conventional Doppler ultrasonography, we determined whether the same vessel was a vein. Blood vessels depicted as black by AccuVein® were also assessed